CN113980652A - Consistent-melting composite phase-change material and preparation method thereof - Google Patents
Consistent-melting composite phase-change material and preparation method thereof Download PDFInfo
- Publication number
- CN113980652A CN113980652A CN202111308658.5A CN202111308658A CN113980652A CN 113980652 A CN113980652 A CN 113980652A CN 202111308658 A CN202111308658 A CN 202111308658A CN 113980652 A CN113980652 A CN 113980652A
- Authority
- CN
- China
- Prior art keywords
- change material
- phase change
- phase
- stirring
- temperature
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000012782 phase change material Substances 0.000 title claims abstract description 132
- 239000002131 composite material Substances 0.000 title claims abstract description 40
- 238000002844 melting Methods 0.000 title claims abstract description 40
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- MFUVDXOKPBAHMC-UHFFFAOYSA-N magnesium;dinitrate;hexahydrate Chemical compound O.O.O.O.O.O.[Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MFUVDXOKPBAHMC-UHFFFAOYSA-N 0.000 claims abstract description 68
- 238000010438 heat treatment Methods 0.000 claims abstract description 57
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims abstract description 54
- 239000000463 material Substances 0.000 claims abstract description 44
- 230000008859 change Effects 0.000 claims abstract description 38
- 230000008018 melting Effects 0.000 claims abstract description 33
- 230000005496 eutectics Effects 0.000 claims abstract description 6
- 238000004146 energy storage Methods 0.000 claims abstract description 5
- 239000011232 storage material Substances 0.000 claims abstract description 4
- 238000003756 stirring Methods 0.000 claims description 27
- 238000001816 cooling Methods 0.000 claims description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000012768 molten material Substances 0.000 claims description 12
- 238000005303 weighing Methods 0.000 claims description 11
- 238000003760 magnetic stirring Methods 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 10
- 239000011159 matrix material Substances 0.000 claims description 8
- 238000010907 mechanical stirring Methods 0.000 claims description 8
- 230000007704 transition Effects 0.000 claims description 8
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 7
- 239000004020 conductor Substances 0.000 claims description 7
- 230000010355 oscillation Effects 0.000 claims description 7
- 229910002804 graphite Inorganic materials 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 5
- 238000007789 sealing Methods 0.000 claims description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical compound [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 239000003575 carbonaceous material Substances 0.000 claims description 4
- 229920002678 cellulose Polymers 0.000 claims description 4
- 239000001913 cellulose Substances 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 239000006260 foam Substances 0.000 claims description 4
- 229910044991 metal oxide Inorganic materials 0.000 claims description 4
- 150000004706 metal oxides Chemical class 0.000 claims description 4
- 239000002121 nanofiber Substances 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 2
- 239000002041 carbon nanotube Substances 0.000 claims description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 2
- 229910021389 graphene Inorganic materials 0.000 claims description 2
- 238000012545 processing Methods 0.000 claims description 2
- 230000002441 reversible effect Effects 0.000 claims description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 2
- 230000001427 coherent effect Effects 0.000 claims 5
- 150000003839 salts Chemical class 0.000 abstract description 11
- 229910052782 aluminium Inorganic materials 0.000 abstract description 9
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 abstract description 9
- 238000004781 supercooling Methods 0.000 abstract description 7
- 239000010935 stainless steel Substances 0.000 abstract description 5
- 229910001220 stainless steel Inorganic materials 0.000 abstract description 5
- 239000002667 nucleating agent Substances 0.000 abstract description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000005191 phase separation Methods 0.000 abstract description 2
- 239000007788 liquid Substances 0.000 description 21
- 238000005338 heat storage Methods 0.000 description 16
- 239000000203 mixture Substances 0.000 description 9
- 238000005260 corrosion Methods 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 8
- 238000013461 design Methods 0.000 description 7
- 238000012360 testing method Methods 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000010963 304 stainless steel Substances 0.000 description 5
- 229910001369 Brass Inorganic materials 0.000 description 5
- 229910000975 Carbon steel Inorganic materials 0.000 description 5
- 229910000589 SAE 304 stainless steel Inorganic materials 0.000 description 5
- 239000010951 brass Substances 0.000 description 5
- 239000010962 carbon steel Substances 0.000 description 5
- 239000003245 coal Substances 0.000 description 5
- 230000005611 electricity Effects 0.000 description 5
- YFQQTCRWBVMXNE-UHFFFAOYSA-N lithium;magnesium;dinitrate;hexahydrate Chemical compound [Li+].O.O.O.O.O.O.[Mg+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O YFQQTCRWBVMXNE-UHFFFAOYSA-N 0.000 description 5
- -1 magnesium nitrate hexahydrate-lithium Chemical compound 0.000 description 5
- BDKLKNJTMLIAFE-UHFFFAOYSA-N 2-(3-fluorophenyl)-1,3-oxazole-4-carbaldehyde Chemical compound FC1=CC=CC(C=2OC=C(C=O)N=2)=C1 BDKLKNJTMLIAFE-UHFFFAOYSA-N 0.000 description 3
- 230000017525 heat dissipation Effects 0.000 description 3
- 238000006386 neutralization reaction Methods 0.000 description 3
- 235000017281 sodium acetate Nutrition 0.000 description 3
- 229940087562 sodium acetate trihydrate Drugs 0.000 description 3
- WZUKKIPWIPZMAS-UHFFFAOYSA-K Ammonium alum Chemical compound [NH4+].O.O.O.O.O.O.O.O.O.O.O.O.[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O WZUKKIPWIPZMAS-UHFFFAOYSA-K 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000004378 air conditioning Methods 0.000 description 2
- ZUDYPQRUOYEARG-UHFFFAOYSA-L barium(2+);dihydroxide;octahydrate Chemical compound O.O.O.O.O.O.O.O.[OH-].[OH-].[Ba+2] ZUDYPQRUOYEARG-UHFFFAOYSA-L 0.000 description 2
- 238000009423 ventilation Methods 0.000 description 2
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/02—Materials undergoing a change of physical state when used
- C09K5/06—Materials undergoing a change of physical state when used the change of state being from liquid to solid or vice versa
- C09K5/063—Materials absorbing or liberating heat during crystallisation; Heat storage materials
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Thermal Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a consistent-melting composite phase-change material and a preparation method thereof, belonging to the technical field of phase-change energy storage materials. The consistent melting composite phase change material comprises a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material; wherein the main phase-change material is magnesium nitrate hexahydrate, and the content of the main phase-change material in the phase-change material is 60-70 mol%; the secondary phase-change material is lithium nitrate, and the content of the secondary phase-change material in the phase-change material is 30-40 mol%; and the heat conduction material accounts for 0-5 wt% of the sum of the main phase change material and the auxiliary phase change material, and the content is not 0. The phase change temperature of the main phase change material can be adjusted by utilizing the secondary phase, the problems of large supercooling degree and serious phase separation of a single hydrous salt phase change material can be solved by the eutectic phase change material, and a nucleating agent is not required to be added in the preparation process because the supercooling degree of the phase change material is extremely small; the phase-change material has good compatibility with aluminum and stainless steel 304, and is beneficial to wide application in the field of clean heating.
Description
Technical Field
The invention belongs to the technical field of phase change energy storage materials, and relates to a consistent-melting composite phase change material and a preparation method thereof.
Background
At present, the proportion of heating energy consumption in China is more than 7%, and with the vigorous promotion of energy revolution in China and the recent carbon peak reaching and carbon neutralization targets, clean heating rapidly rises to be a great strategic demand in China. According to the northern area winter clean heating program, by 2021 years, the northern area clean heating rate reaches 70%, and 1.5 hundred million tons of bulk coal are replaced. In recent years, under the policy of 'coal to electricity' in China, clean heating in winter is carried out in northern areas of China in most cases by changing coal to electricity, and the aim of reducing coal burning heating is fulfilled. Because most urban power grids in China currently execute a 'peak-valley electricity price' policy, the day-night electricity price difference is as much as 3-5 times, if cheap electric energy at night can be utilized, the electric energy is converted into heat energy to be stored, and the heat energy is released at the peak of electricity consumption in daytime, so that the electric energy is used for industrial production heat, resident heating heat and the like, the operation cost of users is greatly reduced, and the use of traditional energy sources such as coal and the like is reduced. The method has good effects in the aspects of realizing peak load shifting of the power grid, stable and efficient operation of the power grid, improvement of the efficiency of the power grid and the like by utilizing the valley-electricity phase change heat storage. The phase change heat storage utilizes the material to absorb (release) a large amount of latent heat in the phase change process so as to achieve the purposes of energy storage and controllable release. Compared with the water heat storage and solid heat storage modes applied in the current clean heating engineering, the phase change heat storage technology utilizes latent heat to store heat, and has the advantages of high heat storage density, constant temperature of latent heat storage/release process, easy process control, small system volume and the like.
The inorganic phase change material, especially the hydrated salt phase change material has the advantages of high heat storage density, relatively high heat conductivity coefficient, nonflammability, low cost and the like, so the inorganic phase change material has good application prospect in the field of clean heating. The inorganic phase change material has wide application range, and has relatively great phase change heat and fixed melting point. Compared with organic phase-change materials, the crystalline hydrated salt has the advantages of higher heat conductivity coefficient, high density, high heat storage density per unit volume and the like. However, the crystalline hydrated salt has the disadvantages of large supercooling degree, phase separation, easy agglomeration and the like.
The inorganic hydrated salt for heating building mainly comprises ammonium aluminum sulfate dodecahydrate, barium hydroxide octahydrate and sodium acetate trihydrate. Wherein: the phase transition temperature of the ammonium aluminum sulfate dodecahydrate is 95 ℃, but the phase transition temperature is higher for specific use occasions, and the problems of weak acidity and high supercooling degree are solved; barium hydroxide octahydrate has high phase change temperature (78 ℃) and phase change latent heat (265.7kJ/kg), but has certain corrosivity and belongs to dangerous chemicals; the phase change temperature of the sodium acetate trihydrate is 58.0 ℃, the latent heat value is high, the heat storage temperature region is relatively low, and the sodium acetate trihydrate is generally suitable for radiant heating. Therefore, the existing hydrated salt phase-change material suitable for the heating requirement of the radiator has lower selectivity.
At present, the heating and radiating tail end of the building in China mainly adopts the modes of heating by a radiator, radiating heating and the like. Taking a system taking hot water as a heating medium as an example, according to the design specification GB50736-2012 of heating, ventilation and air conditioning of civil buildings, the radiant heating and water supply temperature of the floor is preferably 35-45 ℃ and is not more than 60 ℃; the heating and water supply temperature of the radiator is preferably 75 ℃ and is not more than 80 ℃. The phase change temperature and the heat release speed of the materials in the heat storage system are matched with the working temperature of the heat dissipation end, otherwise, the efficiency of the heating system is reduced.
The magnesium nitrate hexahydrate considered by the application has the phase change temperature of 89 ℃, the latent heat of phase change is as high as 150kJ/kg, the cost is low, the environment is friendly, the fields of radiator heating, solar hot water and the like can be met, but the technical problem that the working temperature of the heat storage end is not matched with the working temperature zone of the heat dissipation end still exists.
Particularly, when magnesium nitrate hexahydrate is used as a single-phase hydrous salt phase-change material for the tail end of a radiator, the inventor finds that the temperature of the phase-change temperature zone of the magnesium nitrate hexahydrate is different from the tail end temperature of the radiator in the heating ventilation and air conditioning design of civil buildings to a certain extent. On the basis, the problem to be solved urgently is how to regulate and control the phase-change temperature zone of the magnesium nitrate hexahydrate to enable the working temperature of the heat storage end to be highly matched with the working temperature zone of the heat dissipation end, so that the standard design requirement of specific application of clean heating is met.
Disclosure of Invention
The invention solves the technical problem of technical mismatching between a phase change temperature zone of magnesium nitrate hexahydrate as a single-phase hydrated salt phase change material and the tail end temperature of a radiator.
In order to solve the technical problems, the invention provides the following technical scheme:
the consistent melting composite phase change material comprises a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material; wherein,
the main phase-change material is magnesium nitrate hexahydrate, and the content of the main phase-change material in the phase-change material is 60-70 mol%;
the secondary phase-change material is lithium nitrate, and the content of the secondary phase-change material in the phase-change material is 30-40 mol%;
and the heat conduction material accounts for 0-5 wt% of the sum of the main phase change material and the auxiliary phase change material, and the content is not 0.
Preferably, the heat conduction coefficient of the heat conduction material is 50-200 W.m-1·K-1。
Preferably, the heat conductive material is one or more of a metal matrix, a metal oxide matrix, and a carbon material.
Preferably, the metal matrix is selected from one or more of silver foam, copper foam, nano silver and nano copper; the metal oxide matrix is selected from one or more of nano aluminum oxide and nano titanium oxide; the carbon material is selected from one or more of carbon nano tube, graphene, nano graphite, expanded graphite or cellulose nano fiber.
Preferably, the preparation method of the consistent melting composite phase change material comprises the following steps:
s1, weighing magnesium nitrate hexahydrate and lithium nitrate according to the components and content selection of the consistent melting phase-change material;
s2, pouring the magnesium nitrate hexahydrate and the lithium nitrate weighed in the step S1 into a container, uniformly stirring, putting a magnetic stirrer, and sealing the container;
s3, heating the container in the step S2 on a magnetic heating stirrer in a water bath at the set temperature of 90-100 ℃, and after the sample is melted, starting magnetic stirring and fully stirring for 0.5-1h to obtain a eutectic material;
and S4, cooling and solidifying the eutectic material obtained in the step S3 to obtain the consistent melting composite phase change material with the phase change temperature of 75 +/-5 ℃.
Preferably, the preparation method of the consistent melting composite phase change material further comprises the following steps:
s5, heating the consistent melting composite phase change material with the temperature of 75 +/-5 ℃ prepared in the step S4 in a beaker with the temperature of 75-100 ℃ until the consistent melting composite phase change material is completely melted;
s6, slowly pouring a heat conduction material with the content of 0-5 wt% of the sum of the main phase change material and the auxiliary phase change material into the beaker of S5, heating and stirring for 0.5-1h until completely mixing to obtain a mixed molten material;
s7, when the heat conducting materials in the step S6 are granular, taking out the mixed molten materials in the step S6, and carrying out ultrasonic oscillation for 0.5-1 h; when the heat conducting material in the step S6 is porous, ultrasonic oscillation processing is not required;
s8, cooling and solidifying the material obtained in the step S7 to room temperature, and thus obtaining the consistent melting composite phase change material with higher heat conductivity and required phase change temperature of 75 +/-5 ℃.
Preferably, in step S2, when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are more than 50kg, the stirring manner is mechanical stirring; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are below 0.5kg, magnetic stirring is adopted in a stirring mode; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are between 0.5 and 50kg, the stirring mode adopts mechanical stirring or magnetic stirring.
Preferably, in step S6, when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are more than 50kg, the stirring manner is mechanical stirring; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are below 0.5kg, magnetic stirring is adopted in a stirring mode; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are between 0.5 and 50kg, the stirring mode adopts mechanical stirring or magnetic stirring.
Preferably, the phase transition temperature of the magnesium nitrate hexahydrate is 89 ℃, and the phase transition latent heat is up to 150 kJ/kg.
Preferably, the phase change temperature of the consistent melting composite phase change energy storage material is 75 +/-5 ℃, the phase change latent heat is not less than 170kJ/kg, and the phase change process is reversible.
The technical scheme provided by the embodiment of the invention at least has the following beneficial effects:
in the scheme, in order to solve the contradiction between the phase transition temperature of the single inorganic hydrous salt and the specific application temperature region, the consistent-melting composite phase-change material is prepared by adding one or more eutectic materials synthesized by phase-change materials, and the phase transition temperature of the consistent-melting composite phase-change material can be effectively changed. However, the research on the composite phase change material (70-80 ℃) required by a proper terminal radiator is rarely reported.
The consistent melting composite phase change material comprises a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material, the main phase change material is magnesium nitrate hexahydrate, the auxiliary phase change material is lithium nitrate, and the heat conduction material has a heat conduction coefficient of 50-200 W.m-1·K-1The material of (1).
The supercooling degree of the consistent melting composite phase change material is extremely low, so that a nucleating agent is not required to be added, and the temperature is about 1.76 ℃.
The phase change temperature region of the consistent melting composite phase change material is 75 +/-5 ℃, the heating design requirement of a radiator in the building heating design specification is met, and the phase change material has good compatibility with aluminum and stainless steel 304, can be applied to the field of hydrated salt phase change heat storage clean heating in a large scale, and conforms to the strategic plan of carbon peaking and carbon neutralization currently proposed by China.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a DSC of a phase change material consistent with melting of example 2 of the present invention;
FIG. 2 is a graph of the heating and cooling curves for a consistent melt composite phase change material of example 2 of the present invention;
FIG. 3 is a graph comparing the corrosion of the phase change material of example 2 with carbon steel, aluminum, 304 stainless steel and brass; wherein a, b, c and d are respectively four metal surfaces of carbon steel, aluminum, 304 stainless steel and brass before corrosion, and e, f, g and h are respectively four metal surfaces of carbon steel, aluminum, 304 stainless steel and brass after corrosion for 360 h.
Detailed Description
In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.
Example 1
Weighing 50g of materials, wherein the magnesium nitrate hexahydrate accounts for 60 mol%, and the lithium nitrate accounts for 40 mol%, uniformly mixing, putting into a magnetic stirrer, and sealing the container; heating in water bath on a constant-temperature magnetic stirrer to a constant 95 ℃, after completely melting to a liquid state, magnetically stirring for 30min to ensure uniform mixing until the mixture is in a uniform liquid state, and shaking the beaker to have obvious liquid flowing traces; cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate consistent melting phase-change material.
Example 2
Weighing 50g of the material in example 1, heating the material in a beaker to be liquid, adding 2.5 wt% of expanded graphite into the beaker, heating and stirring the mixture for 30min until the mixture is completely and uniformly mixed to obtain a mixed molten material, and then cooling and solidifying the mixed molten material to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate-expanded graphite composite phase-change material.
Example 3
Weighing 60g of materials, wherein 70 mol% of magnesium nitrate hexahydrate and 30 mol% of lithium nitrate are uniformly mixed, putting a magnetic stirrer and sealing a container; heating in water bath on a constant temperature magnetic stirrer to a constant 93 ℃, after completely melting to be liquid, magnetically stirring for 40min to ensure uniform mixing until the mixture is in a uniform liquid state, and shaking the beaker to have obvious liquid flowing traces; cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate consistent melting phase-change material.
Example 4
60g of the material in example 1 is weighed, heated to be liquid in a beaker, 1.5 wt% of foamed silver is added into the beaker, heated and stirred for 40min until the mixture is completely and uniformly mixed to obtain a mixed molten material, and then the mixed molten material is cooled and solidified to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate-foamed silver composite phase-change material.
Example 5
Weighing 20kg of materials, wherein the magnesium nitrate hexahydrate accounts for 65 mol%, and the lithium nitrate accounts for 35 mol%, uniformly mixing, putting into a magnetic stirrer, and sealing the container; heating in water bath on a constant-temperature magnetic stirrer to a constant 97 ℃, after completely melting to a liquid state, magnetically stirring for 55min to ensure uniform mixing until the mixture is in a uniform liquid state, and shaking the beaker to have obvious liquid flowing traces; cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate consistent melting phase-change material.
Example 6
Weighing 20kg of the material in example 1, heating the material to a liquid state, adding 4.5 wt% of nano-alumina, heating and stirring for 55min until the material is completely and uniformly mixed to obtain a mixed molten material, performing ultrasonic oscillation for 40min, and then cooling and solidifying the material to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate-nano-alumina composite phase-change material.
Example 7
Weighing 40kg of materials, wherein the magnesium nitrate hexahydrate accounts for 63 mol%, and the lithium nitrate accounts for 37 mol%, uniformly mixing, heating in a water bath on a mechanical stirrer to a constant 100 ℃ until the magnesium nitrate hexahydrate and the lithium nitrate are completely melted into a liquid state, mechanically stirring for 45min to ensure uniform mixing until the mixture is in a uniform liquid state, and shaking a beaker to have obvious liquid flowing traces; cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate consistent melting phase-change material.
Example 8
Weighing 40kg of the material in example 1, heating the material to a liquid state, adding 3.5 wt% of nano-silver, heating and mechanically stirring for 45min until the material is completely and uniformly mixed to obtain a mixed molten material, carrying out ultrasonic oscillation for 50min, and then cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate-nano-silver composite phase-change material.
Example 9
Weighing 60kg of materials, wherein 67 mol% of magnesium nitrate hexahydrate and 33 mol% of lithium nitrate are uniformly mixed, heating the materials in a water bath on a mechanical stirrer to a constant 98 ℃ until the materials are completely melted into a liquid state, mechanically stirring the materials for 55min to ensure uniform mixing until the mixture is in a uniform liquid state, and shaking a beaker to have obvious liquid flowing traces; cooling and solidifying to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate consistent melting phase-change material.
Example 10
Weighing 60kg of the material in example 1, heating the material to a liquid state, adding 3.3 wt% of cellulose nanofiber, heating and mechanically stirring for 55min until the mixture is completely and uniformly mixed to obtain a mixed molten material, performing ultrasonic oscillation for 60min, and then cooling and solidifying the mixed molten material to room temperature to obtain the magnesium nitrate hexahydrate-lithium nitrate-cellulose nanofiber composite phase-change material.
Performance testing
The phase change materials obtained in the above examples 1 to 10 were tested by the following test methods, and the test results are shown in table 1:
s1, measuring the phase change temperature and the latent heat of phase change of the phase change materials obtained in the embodiments 1 to 10 by using a Differential Scanning Calorimeter (DSC) under the nitrogen flow of 50ml/min and the heating and cooling rates of 10 ℃/min; wherein the phase change temperature and the latent heat of phase change of the phase change material of example 2 are shown in FIG. 1; in fig. 1: the temperature corresponding to the inflection point of the curve is the phase change temperature of the phase change material obtained in example 2, and the peak area enclosed by the horizontal line and the curve is the latent heat of phase change of the phase change material obtained in example 2; it can be concluded therefrom that the phase change material obtained in example 2 has a phase change temperature of 72.89 ℃ and a latent heat of phase change of 171.79J/g.
S2, heating cooling curve: pouring the phase change material into a test tube in a liquid state, inserting a thermocouple, cooling to room temperature, then heating in a water bath kettle at 95 ℃, and naturally cooling in air after the temperature reaches the water bath temperature to obtain the heating and cooling curve of the phase change material obtained in the embodiment 1 to 10; wherein the heating-cooling curve of the phase change material of example 2 is shown in fig. 2; the phase-change material obtained in the embodiment 2 has an obvious heat release platform, a proper phase-change temperature and a small supercooling degree, and can be widely applied to the field of phase-change heat storage and clean heating.
S3, corrosion test: preparing four metal corrosion sheets of carbon steel, aluminum, 304 stainless steel and brass, placing the four metal corrosion sheets in a test tube containing the phase change material obtained in the embodiment 1-10, heating the test tube in an oven at 85 ℃ for 360 hours, taking out the test tube after 360 hours, observing the surface condition of the metal and judging the corrosivity of the metal corrosion sheet; wherein, the metal surface condition of the phase-change material of the embodiment 2 before and after the corrosion of four metals of carbon steel, aluminum, 304 stainless steel and brass is shown in figure 3; it can be concluded that the phase change material obtained in example 2 is less corrosive to aluminum and stainless steel 304, and in particular to stainless steel 304.
S4, thermal conductivity: the thermal conductivity of the phase change materials of examples 1-10 were tested using the thermal constant analyzer TPS 2500S of Hot Disk, Sweden;
the process parameters of the phase change material measured for specific examples 1-10 are shown in table 1 below.
TABLE 1 thermal conductivity of examples 1-10
In the scheme, the consistent-melting composite phase change material comprises a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material, the main phase change material is magnesium nitrate hexahydrate, the auxiliary phase change material is lithium nitrate, and the heat conduction material has a heat conduction coefficient of 50-200 W.m-1·K-1The material of (1).
The supercooling degree of the consistent melting composite phase change material is extremely low, so that a nucleating agent is not required to be added, and the temperature is about 1.76 ℃.
The phase change temperature region of the consistent melting composite phase change material is 75 +/-5 ℃, the heating design requirement of a radiator in the building heating design specification is met, and the phase change material has good compatibility with aluminum and stainless steel 304, can be applied to the field of hydrated salt phase change heat storage clean heating in a large scale, and conforms to the strategic plan of carbon peaking and carbon neutralization currently proposed by China.
While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (10)
1. The consistent melting composite phase change material is characterized by comprising a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material; wherein,
the main phase-change material is magnesium nitrate hexahydrate, and the content of the main phase-change material in the phase-change material is 60-70 mol%;
the secondary phase-change material is lithium nitrate, and the content of the secondary phase-change material in the phase-change material is 30-40 mol%;
and the heat conduction material accounts for 0-5 wt% of the sum of the main phase change material and the auxiliary phase change material, and the content is not 0.
2. The coherent melt composite phase change material of claim 1, wherein the thermally conductive material has a thermal conductivity of 50-200W-m-1·K-1。
3. The coherent melt composite phase change material of claim 2, wherein the thermally conductive material is one or more of a metal matrix, a metal oxide matrix, and a carbon material.
4. The coherent melt composite phase change material of claim 3, wherein the metal matrix is selected from one or more of silver foam, copper foam, nano silver, and nano copper; the metal oxide matrix is selected from one or more of nano aluminum oxide and nano titanium oxide; the carbon material is selected from one or more of carbon nano tube, graphene, nano graphite, expanded graphite or cellulose nano fiber.
5. A method for preparing an coherent melt composite phase change material according to any of claims 1 to 4, wherein the method for preparing the coherent melt composite phase change material comprises the steps of:
s1, weighing magnesium nitrate hexahydrate and lithium nitrate according to the components and content selection of the consistent melting phase-change material;
s2, pouring the magnesium nitrate hexahydrate and the lithium nitrate weighed in the step S1 into a container, uniformly stirring, putting a magnetic stirrer, and sealing the container;
s3, heating the container in the step S2 on a magnetic heating stirrer in a water bath at the set temperature of 90-100 ℃, and after the sample is melted, starting magnetic stirring and fully stirring for 0.5-1h to obtain a eutectic material;
and S4, cooling and solidifying the eutectic material obtained in the step S3 to obtain the consistent melting composite phase change material with the phase change temperature of 75 +/-5 ℃.
6. The method of claim 5, further comprising the steps of:
s5, heating the consistent melting composite phase change material with the temperature of 75 +/-5 ℃ prepared in the step S4 in a beaker with the temperature of 75-100 ℃ until the consistent melting composite phase change material is completely melted;
s6, slowly pouring a heat conduction material with the content of 0-5 wt% of the sum of the main phase change material and the auxiliary phase change material into the beaker of S5, heating and stirring for 0.5-1h until completely mixing to obtain a mixed molten material;
s7, when the heat conducting materials in the step S6 are granular, taking out the mixed molten materials in the step S6, and carrying out ultrasonic oscillation for 0.5-1 h; when the heat conducting material in the step S6 is porous, ultrasonic oscillation processing is not required;
s8, cooling and solidifying the material obtained in the step S7 to room temperature, and thus obtaining the consistent melting composite phase change material with higher heat conductivity and required phase change temperature of 75 +/-5 ℃.
7. The method for preparing the phase change material according to claim 5, wherein in step S2, when the preparation amounts of magnesium nitrate hexahydrate and lithium nitrate are more than 50kg, the stirring manner is mechanical stirring; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are below 0.5kg, magnetic stirring is adopted in a stirring mode; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are between 0.5 and 50kg, the stirring mode adopts mechanical stirring or magnetic stirring.
8. The method for preparing the phase change material according to claim 6, wherein in step S6, when the preparation amounts of magnesium nitrate hexahydrate and lithium nitrate are more than 50kg, the stirring manner is mechanical stirring; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are below 0.5kg, magnetic stirring is adopted in a stirring mode; when the preparation amounts of the magnesium nitrate hexahydrate and the lithium nitrate are between 0.5 and 50kg, the stirring mode adopts mechanical stirring or magnetic stirring.
9. The method of claim 5, wherein the magnesium nitrate hexahydrate has a phase transition temperature of 89 ℃ and a latent heat of phase transition of up to 150 kJ/kg.
10. The method for preparing the uniform melting composite phase change material as claimed in claim 5, wherein the phase change temperature of the uniform melting composite phase change energy storage material is 75 ± 5 ℃, the latent heat of phase change is not less than 170kJ/kg, and the phase change process is reversible.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111308658.5A CN113980652A (en) | 2021-11-05 | 2021-11-05 | Consistent-melting composite phase-change material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111308658.5A CN113980652A (en) | 2021-11-05 | 2021-11-05 | Consistent-melting composite phase-change material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113980652A true CN113980652A (en) | 2022-01-28 |
Family
ID=79746908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111308658.5A Pending CN113980652A (en) | 2021-11-05 | 2021-11-05 | Consistent-melting composite phase-change material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113980652A (en) |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3929900A1 (en) * | 1989-09-08 | 1991-03-14 | Nikolaos Dr Malatidis | Phase change-type heat storage materials - based on hydrated magnesium nitrate |
| DE4141306A1 (en) * | 1991-12-14 | 1993-06-17 | Merck Patent Gmbh | Salt mixt. of magnesium nitrate and lithium nitrate - for heat storage and recovery by phase change, esp. for storing waste heat from motor vehicles |
| DE4203835A1 (en) * | 1992-02-10 | 1993-08-12 | Bayerische Motoren Werke Ag | Salt mixts. of magnesium nitrate hexa:hydrate and lithium nitrate |
| AU3236499A (en) * | 1998-06-02 | 1999-12-09 | Modine Manufacturing Company | Density stabilized phase change material |
| CN101289610A (en) * | 2008-06-14 | 2008-10-22 | 西部矿业股份有限公司 | Phase-change and energy-storage medium at room temperature and method for preparing same |
| CN102352221A (en) * | 2011-10-20 | 2012-02-15 | 天津科技大学 | High-performance medium-temperature inorganic phase-change material and preparation method thereof |
| CN107198458A (en) * | 2017-06-26 | 2017-09-26 | 张绍乙 | Self-heating/cooling and phase transformation store device and its application method that insulation is combined |
| CN108251074A (en) * | 2018-01-03 | 2018-07-06 | 北京今日能源科技发展有限公司 | A kind of 89 degree of phase-changing energy storage materials |
| CN108485610A (en) * | 2018-04-19 | 2018-09-04 | 华南理工大学 | Organic-inorganic composite phase-change material based on magnesium nitrate hexahydrate and preparation method thereof |
| CN109233752A (en) * | 2018-11-21 | 2019-01-18 | 江苏昂彼特堡能源科技有限公司 | A kind of inorganic hydrated salt composite phase-change heat-storage material and preparation method thereof |
| CN109609098A (en) * | 2018-12-12 | 2019-04-12 | 上海交通大学 | A kind of composite phase-change heat-storage material and its preparation |
| CN110066642A (en) * | 2019-04-09 | 2019-07-30 | 中国科学院过程工程研究所 | 89 ± 7 DEG C of phase transition temperature of phase-changing energy storage material and preparation method thereof |
| CN110564373A (en) * | 2019-09-16 | 2019-12-13 | 北京华厚能源科技有限公司 | Inorganic hydrated salt composite phase-change heat storage material and preparation and use method thereof |
| CN111978926A (en) * | 2019-05-22 | 2020-11-24 | 陕西运维电力股份有限公司 | Medium-temperature phase-change material based on clean heating |
| CN111978925A (en) * | 2019-05-22 | 2020-11-24 | 陕西运维电力股份有限公司 | Composite phase-change material for cleaning and heating and preparation method thereof |
-
2021
- 2021-11-05 CN CN202111308658.5A patent/CN113980652A/en active Pending
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3929900A1 (en) * | 1989-09-08 | 1991-03-14 | Nikolaos Dr Malatidis | Phase change-type heat storage materials - based on hydrated magnesium nitrate |
| DE4141306A1 (en) * | 1991-12-14 | 1993-06-17 | Merck Patent Gmbh | Salt mixt. of magnesium nitrate and lithium nitrate - for heat storage and recovery by phase change, esp. for storing waste heat from motor vehicles |
| DE4203835A1 (en) * | 1992-02-10 | 1993-08-12 | Bayerische Motoren Werke Ag | Salt mixts. of magnesium nitrate hexa:hydrate and lithium nitrate |
| AU3236499A (en) * | 1998-06-02 | 1999-12-09 | Modine Manufacturing Company | Density stabilized phase change material |
| CN1239132A (en) * | 1998-06-02 | 1999-12-22 | 穆丹制造公司 | Density stabilized phase change material |
| CN101289610A (en) * | 2008-06-14 | 2008-10-22 | 西部矿业股份有限公司 | Phase-change and energy-storage medium at room temperature and method for preparing same |
| CN102352221A (en) * | 2011-10-20 | 2012-02-15 | 天津科技大学 | High-performance medium-temperature inorganic phase-change material and preparation method thereof |
| CN107198458A (en) * | 2017-06-26 | 2017-09-26 | 张绍乙 | Self-heating/cooling and phase transformation store device and its application method that insulation is combined |
| CN108251074A (en) * | 2018-01-03 | 2018-07-06 | 北京今日能源科技发展有限公司 | A kind of 89 degree of phase-changing energy storage materials |
| CN108485610A (en) * | 2018-04-19 | 2018-09-04 | 华南理工大学 | Organic-inorganic composite phase-change material based on magnesium nitrate hexahydrate and preparation method thereof |
| CN109233752A (en) * | 2018-11-21 | 2019-01-18 | 江苏昂彼特堡能源科技有限公司 | A kind of inorganic hydrated salt composite phase-change heat-storage material and preparation method thereof |
| CN109609098A (en) * | 2018-12-12 | 2019-04-12 | 上海交通大学 | A kind of composite phase-change heat-storage material and its preparation |
| CN110066642A (en) * | 2019-04-09 | 2019-07-30 | 中国科学院过程工程研究所 | 89 ± 7 DEG C of phase transition temperature of phase-changing energy storage material and preparation method thereof |
| CN111978926A (en) * | 2019-05-22 | 2020-11-24 | 陕西运维电力股份有限公司 | Medium-temperature phase-change material based on clean heating |
| CN111978925A (en) * | 2019-05-22 | 2020-11-24 | 陕西运维电力股份有限公司 | Composite phase-change material for cleaning and heating and preparation method thereof |
| CN110564373A (en) * | 2019-09-16 | 2019-12-13 | 北京华厚能源科技有限公司 | Inorganic hydrated salt composite phase-change heat storage material and preparation and use method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 次恩达: "六水硝酸镁-硝酸锂共晶盐/膨胀石墨复合相变材料的制备及性能强化", 《储能科学与技术》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Tian et al. | Enhanced thermal conductivity of ternary carbonate salt phase change material with Mg particles for solar thermal energy storage | |
| Xiao et al. | The shape-stabilized light-to-thermal conversion phase change material based on CH3COONa· 3H2O as thermal energy storage media | |
| Liu et al. | Development of low-temperature eutectic phase change material with expanded graphite for vaccine cold chain logistics | |
| Jin et al. | Thermal conductivity enhancement of a sodium acetate trihydrate–potassium chloride–urea/expanded graphite composite phase–change material for latent heat thermal energy storage | |
| CN103923619B (en) | Molten nano-carbonate heat transfer and accumulation medium, and preparation method and application thereof | |
| US10351748B2 (en) | Nanometer molten salt heat-transfer and heat-storage medium, preparation method and use thereof | |
| CN103113854B (en) | A kind of mobile heat supply composite phase-change material and preparation method thereof | |
| CN104559942A (en) | Mixed molten salt heat storage and heat transfer material and preparation method thereof | |
| CN104710965A (en) | Method for preparing multilevel porous carbon base composite phase change material | |
| CN103881662A (en) | Ternary nitric acid nano-molten salt heat transfer and storage medium, preparation method and application thereof | |
| CN110066642B (en) | Phase change energy storage material with phase change temperature of 89 +/-7 ℃ and preparation method thereof | |
| CN109609098B (en) | Composite phase-change heat storage material and preparation thereof | |
| Li et al. | Stearic acid/copper foam as composite phase change materials for thermal energy storage | |
| CN104804712B (en) | The metal chloride fused salt material and preparation method of a kind of high heat conduction and application | |
| CN104610927A (en) | Low-melting-point mixed fused salt heat storage and heat transfer material and preparation method thereof | |
| CN103756647A (en) | Particle-molten salt compound heat-transferring and heat-accumulating medium material and preparation method thereof | |
| CN113214796B (en) | Composite inorganic salt phase change cold storage agent and preparation method thereof | |
| CN105154021A (en) | Highly heat-conducting phase change heat storage material and preparation method therefor | |
| Hua et al. | Preparation of modified sodium acetate trihydrate and the thermodynamic analysis | |
| CN107084634A (en) | A kind of long-distance transmissions with heat bridge effect store heat radiation structure | |
| CN110564373A (en) | Inorganic hydrated salt composite phase-change heat storage material and preparation and use method thereof | |
| CN101974313B (en) | Phase change thermal storage material and manufacturing method thereof | |
| CN113004875A (en) | Chloride-based nano molten salt heat transfer and storage medium and application and preparation method thereof | |
| CN102321455A (en) | Warm phase change heat storage material in a kind of | |
| CN113980652A (en) | Consistent-melting composite phase-change material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |